chore: add encrypt function

Author: genu

packages/runtime/src/enhancements/node/encrypted.ts

@@ -0,0 +1,109 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+/* eslint-disable @typescript-eslint/no-unused-vars */
+
+import { NestedWriteVisitor, type PrismaWriteActionType } from '../../cross';
+import { DbClientContract } from '../../types';
+import { InternalEnhancementOptions } from './create-enhancement';
+import { DefaultPrismaProxyHandler, PrismaProxyActions, makeProxy } from './proxy';
+
+/**
+ * Gets an enhanced Prisma client that supports `@encrypted` attribute.
+ *
+ * @private
+ */
+export function withEncrypted<DbClient extends object = any>(
+    prisma: DbClient,
+    options: InternalEnhancementOptions
+): DbClient {
+    return makeProxy(
+        prisma,
+        options.modelMeta,
+        (_prisma, model) => new EncryptedHandler(_prisma as DbClientContract, model, options),
+        'encrypted'
+    );
+}
+
+const encoder = new TextEncoder();
+const decoder = new TextDecoder();
+
+const getKey = async (secret: string): Promise<CryptoKey> => {
+    return crypto.subtle.importKey('raw', encoder.encode(secret).slice(0, 32), 'AES-GCM', false, [
+        'encrypt',
+        'decrypt',
+    ]);
+};
+const encryptFunc = async (data: string, secret: string): Promise<string> => {
+    const key = await getKey(secret);
+    const iv = crypto.getRandomValues(new Uint8Array(12));
+
+    const encrypted = await crypto.subtle.encrypt(
+        {
+            name: 'AES-GCM',
+            iv,
+        },
+        key,
+        encoder.encode(data)
+    );
+
+    // Combine IV and encrypted data into a single array of bytes
+    const bytes = [...iv, ...new Uint8Array(encrypted)];
+
+    // Convert bytes to base64 string
+    return btoa(String.fromCharCode(...bytes));
+};
+
+const decryptFunc = async (encryptedData: string, secret: string): Promise<string> => {
+    const key = await getKey(secret);
+
+    // Convert base64 back to bytes
+    const bytes = Uint8Array.from(atob(encryptedData), (c) => c.charCodeAt(0));
+
+    // First 12 bytes are IV, rest is encrypted data
+    const decrypted = await crypto.subtle.decrypt(
+        {
+            name: 'AES-GCM',
+            iv: bytes.slice(0, 12),
+        },
+        key,
+        bytes.slice(12)
+    );
+
+    return decoder.decode(decrypted);
+};
+
+class EncryptedHandler extends DefaultPrismaProxyHandler {
+    constructor(prisma: DbClientContract, model: string, options: InternalEnhancementOptions) {
+        super(prisma, model, options);
+    }
+
+    // base override
+    protected async preprocessArgs(action: PrismaProxyActions, args: any) {
+        const actionsOfInterest: PrismaProxyActions[] = ['create', 'createMany', 'update', 'updateMany', 'upsert'];
+        if (args && args.data && actionsOfInterest.includes(action)) {
+            await this.preprocessWritePayload(this.model, action as PrismaWriteActionType, args);
+        }
+        return args;
+    }
+
+    // base override
+    protected async processResultEntity(action: PrismaProxyActions, args: any) {
+        return args;
+    }
+
+    private async preprocessWritePayload(model: string, action: PrismaWriteActionType, args: any) {
+        const visitor = new NestedWriteVisitor(this.options.modelMeta, {
+            field: async (field, _action, data, context) => {
+                const encAttr = field.attributes?.find((attr) => attr.name === '@encrypted');
+                if (encAttr && field.type === 'String') {
+                    // encrypt value
+
+                    let secret: string = encAttr.args.find((arg) => arg.name === 'secret')?.value as string;
+
+                    context.parent[field.name] = await encryptFunc(data, secret);
+                }
+            },
+        });
+
+        await visitor.visit(model, action, args);
+    }
+}